This invention relates to certain penems substituted at the 2-position by a heterocyclylthio group, their pharmaceutically acceptable salts and pharmaceutically acceptable esters, which compounds possess potent antibacterial activity and have high serum half-lives.
There is a continuing need for new antibacterial agents because continued extensive use of effective antibacterials gives rise to resistant strains of pathogens.
Antibacterials of the penem-type are known in the art. U.S. Pat. No. 4,272,437 discloses a large number of penems including those with a 6-(1-hydroxyethyl) substituent as shown e.g., in Examples 41, 58, 60, 61, 62, 63, 64, 65, 66 and 96. Examples 64 and 65 disclose penems with the 5R,6S stereochemical structure. There are no disclosures in the patent of penems with a heterocyclylthio at the 2-position.
U.S. Pat. No. 4,301,074 discloses penems with an --SR substituent at the 2-position. The R can be a 5-member heterocyclic group, but not a saturated heterocyclic group.
British Pat. No. 2,013,674A discloses penems with a hydroxyethyl group at the 6-position, but no saturated 5-membered heterocyclylthio groups at the 2-position.